The Charles Schwab Corp. on Monday said a mutual fund clearing services client that began transferring assets led to a $24.8 billion outflow in May.

The brokerage did not identify the client, which pulled $29.5 billion out as part of a plan to switch to an internal trading platform. Other new and existing clients deposited $4.7 billion during the month.

Total client assets fell 7 percent from April, to $1.412 trillion. The major market indexes recorded their worst monthly performance in over a year in May, as investors worried about Europe's debt problems. The Dow Jones industrial average fell 7.9 percent and the broader Standard & Poor's 500 index down 8.2 percent during the month. Total client assets were up 16 percent from a year ago.

Charles Schwab's clients executed an average 512,700 trades a day in May, a 14 percent increase from May 2009.

In morning trading, Schwab shares slipped 13 cents to $16.19. The stock has traded between $15.59 and $19.95 in the past year.